Conveying device for a drop forging press

ABSTRACT

A workpiece conveying device is provided for a drop forge type press which includes parallel conveying means which extend transverse through the frame of the press and are adapted to move in unison to grip and transfer a workpiece to and from the dies of the forging press. A drive control mechanism is provided on each side of the press frame and located above the lower die of the press. The conveying beams are suspended from the control mechanism by the use of spring-biased piston-cylinder units which move the conveying beams in response to the control mechanism. A motor drive assembly is provided for driving the control mechanism and in turn the conveying beams. Two detent gear mechanisms composed of pivoting linkage mechanisms move in separate planes which are arranged perpendicular to each other. The detent gears are designed and are interconnected to effect a predetermined, three-dimensional, closed path motion to the conveying beams. The spring-biased piston-cylinder suspension members are constantly pressurized into the extended position for normal operations. Release of this pressure retracts the conveying beams to provide clearance for removal of the bottom forging die. A safety release connection between the piston and rod of the suspension members permits the conveying beams to be separated to prevent damage to the control mechanism if the beams are inadvertently caught in the forging press ram operation. In another embodiment, the control mechanism is composed of a pair of movable slide plates which are located on opposite sides of the press frames and which are adapted to be moved in unison in two dimensions by the use of fluid motors. The slide plate movement is transferred to the conveying beams and movement of the beams in a gripping or third dimension is provided by a fluid motor-operated toggle mechanism.

il'nited States Patent [191 Berger [451 Sept. 25, 1973 CONVEYING DEVICE FOR A DROP FORGING PRESS [75] Inventor: Rolf Berger, Bergisch-Gladbach,

Germany [22] Filed: Dec. 10, 1971 211 App]. No.: 206,768

[30] Foreign Application Priority Data Primary ExaminerGerald M. Forlenza Assistant Examiner-George F. Abraham Att0rneyNeil F. Markva et al.

[57] ABSTRACT A workpiece conveying device is provided for a drop forge type press which includes parallel conveying means which extend transverse through the frame of the press and are adapted to move in unison to grip and transfer a workpiece to and from the dies of the forging press. A drive control mechanism is provided on each side of the press frame and located above the lower die of the press. The conveying beams are suspended from the control mechanism by the use of spring-biased piston-cylinder units which move the conveying beams in response to the control mechanism. A motor drive assembly is provided for driving the control mechanism and in turn the conveying beams. Two detent gear mechanisms composed of pivoting linkage mechanisms move in separate planes which are arranged perpendicular to each other. The detent gears are designed and are interconnected to effect a predetermined, threedimensional, closed path motion to the conveying beams. The spring-biased piston-cylinder suspension members are constantly pressurized into the extended position for normal operations. Release of this pressure retracts the conveying beams to provide clearance for removal of the bottom forging die. A safety release connection between the piston and rod of the suspension members permits the conveying beams to be separated to prevent damage to the control mechanism if the beams are inadvertently caught in the forging press ram operation. In another embodiment, the control mechanism is composed of a pair of movable slide plates which are located on opposite sides of the press frames and which are adapted to be moved in unison in two dimensions by the use of fluid motors. The slide plate movement is transferred to the conveying beams and movement of the beams in a gripping or third dimension is provided by a fluid motor-operated toggle mechanism.

15 Claims, 10 Drawing Figures PATENTEDSEPZSIQTS 3.760957 sum 5 or 7 LUWER PATENTED FZ 3. 760.957

sum 2 0r 7 FIGJO CONVEYING DEVICE FOR A DROP FORGING PRESS BACKGROUND OF THE INVENTION This invention relates to a workpiece conveying apparatus for use with a drop forging press which provides for automatic movement of a workpiece to and from the forging press dies and more specifically relates to an apparatus whereby the workpiece can be gripped, lifted and reciprocally moved longitudinally by means of gearing mechanisms. In the prior art the conveying systems used with drop forging presses such as the eccentric press, wedge press or the like have their conveyor apparatus positioned below the forging dies. The drives for these systems are also located in this position. The conveying systems of these devices because of their size are also necessarily located to the sides of the press frame as well as below the level of the press. Being at this position, the drive and gearing mechanism is subjected to contamination and wear resulting from the debris and scale generated in the forging operation.

The prior art arrangements, although designed to provide access and clearance around the forging dies, necessitated the imbedding of the conveyor mechanism in the foundation of the press. Thus, although access to the press itself is provided, many repair and maintenance problems occur with the conveyor mechanism in this position. Usually foundation covers and access openings must be removed to provide maintenance to the conveyor mechanism, and the imbedding of the conveyor mechanism in the foundation, in addition, requires an extensively large foundation necessitating increased costs in the construction.

PURPOSE OF THE INVENTION An object of this invention is to provide a conveying apparatus for moving workpieces to and from .the dies of a forging press in an inexpensive, reliable and automatic operation.

Another object is to permit the control mechanism for the operation of the conveying device to be positioned above the inner face of the forging dies in order to prevent the control linkage mechanisms from becoming subjected to debris and contamination and thus reduce the wear normally found in a device of this nature.

' A further object is to provide a workpiece conveying system for a drop forge press which provides access to the press operation around the forging dies and still permits ready access to the actuating mechanism for repairing the conveying system.

A still further object is to provide a conveyor device that is in no way imbedded in the press foundation or directly connected with the foundation to allow a normal, economical foundation to be constructed for the forging press.

Another object of this invention is to provide a conveying device wherein the gripping means must move a minimum distance of travel in feeding and removing workpieces contrary to the long mechanism movements required when a conveyor control gear box is disposed under the forging press.

SUMMARY OF THE INVENTION The conveyor of this invention includes a workpiece gripper arrangement consisting of parallel conveying beams disposed transverse to the press and through or between the support columns of the press frame. The conveying beams are arranged to straddle theforging dies and yet securely grip the workpiece during movement.

Drive control mechanisms are provided on each side of the press frame and are interconnected by a drive shaft to power and synchronize the movements of the conveying beams from each side of the press.

The conveying beams are suspended at each end from the control mechanism by the use of conveying arms. These arms are comprised of piston-cylinder units which are spring-biased towards their retracted position. A constant source of pneumatic pressure is applied to the pistons to extend the rods and lower the conveying beams during normal conveyor operation. Removal of this pressure allows the spring-bias to retract the rods and raise the conveying beams to provide clearance for removal of the bottom forging die as required. A releaseable connection is also provided between the piston rod and piston so that the conveying beam can be released from the conveying arms and drive control mechanism if the beam is caught by an inadvertent or abnormal operation of the forging press ram. Damage to the control mechanism and power mechanism is thus averted. In this manner it becomes possible to achieve a free movement of the conveying beams in the event of an uncontrolled ram stroke. At the same time, easier, simpler and more rapid changing of the dies can be effected.

In this conveyor device, control of the movement of the conveying arms or beams for the longitudinal, transverse and vertical movement is expediently effected with the aid of detent gears. The term detent gears as used in this application defines a linkage mechanism which transmits a predetermined mechanical motion to an object andperiodically locks and unlocks in response to movements of cooperating mechanisms. A pair of detent gears is provided in the drive control mechanism of this device. The linkage of each gear moves so as to define a plane and the individual gears in this mechanism are arranged so that their planes are generally perpendicular to each other. One detent gear controls the longitudinal movement of the conveying beams, while the other controls the opening and closure movement and the lifting movements of the conveying beams. Both of the detent gears are located in a main gear box housing on one side of the press frame and are driven by a reversible motor transmission arrangement through interconnected drive shafts. Mechanical motion is transmitted throughan interconnecting shaft to the auxiliary gear box on the opposite side of the press frame. Thus, mechanical motion gen erated by the control detent gears is imparted to the suspension members or conveying arms attached to the conveying beams. The upper portion of the conveying arms are pivotally connected to a cross beam arrangement in each'gear box. Gear and pinion means is provided in conjunction with the pivotal cross beams to transmit motion from one of the detent gears to toggle linkage arrangements located in each gear box. Raising the toggle link by the rack and pinion assembly causes the suspension arms to move together so as to cause the conveying beams to retract and grip the workpiece. A pneumatic cylinder is provided in conjunction with each rack and pinion assembly to aid in locking the conveying beams in their gripping position during movement of the beams in their vertical or longitudinal direction.

Additional guide means is provided in the form of piston-cylinder units in conjunction with the conveying arms on one side of the forging press. This guiding means provides a pantograph arrangement for stabilizing the conveying beams in a single plane; In addition, screw adjustment means is provided to adjust the position of the guide beams and suspension arms with respect to each other to maintain a parallel condition between the conveying beams.

In another embodiment of this invention, the drive control mechanism can be provided in the form of a pair of slidable plates mounted on each side of the press frame and above the level of the inner face of the forging dies. The conveying arms or suspension members are suspended from the slide plates and adapted to pivot in vertical planes parallel to the respective slide plates. The slide plates are adapted for uniform movement in conjunction with each other by the use of fluid motors or piston-cylinder units, and each slide plate is adapted for transverse or vertical movement. A fluid motor-operated toggle linkage is mounted on each slide plate for extending or retracting the supension members and conveying beams for gripping the workpiece, and the fluid motor itself is positioned on the centerline of the slide plate. A slot located on this centerline serves to guide the toggle links and position the gripping stroke of the conveying beams with respect to the forging dies. The power drive means for this embodiment is provided by a motor-pump assembly which provides fluid pressure for movement of the fluid motor units. A control device for operating fluid valves by means of cam arrangements can be provided. The cams are designed to provide the predetermined sequential movement of the conveying beams that is desired. Other control means such as the detent gearing arrangement described above can be used to actuate the fluid control valves necessary to properly operate the conveying device of this invention.

BRIEF DESCRIPTION OF DRAWINGS Other features of this invention will appear in the following description and appended claims, reference being made to the accompanying drawings forming a part of the specification when like reference characters designate corresponding parts in the several views.

FIG. I shows a front elevation view partly in section of a drop forge press which includes the conveyor mechanism of the present invention, the sectional part being taken along the line I-I of FIG.

FIG. 2 shows a partial sectional view through the main gear box of the present invention taken along the line 11-" of FIG. 1;

FIG. 3 is a side elevational view partly in section of the press and conveyor mechanism taken along the line III-III of FIG. 1;

FIG. 4 is a sectional plan view of the conveying beams of this invention taken along the line IV-IV of FIG. 1;

FIG. 5 is a side elevational view partly in section of the conveyor mechanism of this invention viewed in the direction of arrow V of FIG. 1;

FIG. 6 is a top plan view of the main gear box of FIG. 5 showing the drive transmission shafts of the conveyor mechanism in phantom lines;

FIG. 7 is a diagram illustrating the movement of the conveying beams during operation;

FIG. 8 shows in diagrammatic, circular form the angular components of the individual movements during a power cycle;

FIG. 9 shows a partial elevational view partly in section of a drop forge press incorporating another embodiment of the conveyor mechanism of this invention; and

FIG. 10 is a side elevational view partly in section of the embodiment of FIG. 9 taken along the line XX of FIG. 9.

DESCRIPTION OF SPECIFIC EMBODIMENTS A drop forging press 1 such as an eccentric press or a wedge press is shown in FIG. I. The press 1 has a frame 2 which consists of four columns or posts 3, 4, 5, 6. A piston ram carrying the upper die 9 is displaced in a vertical reciprocating motion by an eccentric drive. The lower die 10 which cooperates with the upper die usually remains stationary. Disposed on one side of the press frame 2 is the clutch 7 positioned between the press drive apparatus and the eccentric ram shaft. On the other side of the press frame 2 is arranged a braking device 8 for the ram. The eccentric drive clutch and brake perform in a manner which is well known in the art.

An automatic conveying means for moving the workpieces to and from the forging dies is provided. This conveying means includes a pair of conveying beams l6, 17 which extend laterally through the press frame 2 and at the level of the lower die 10. The conveying beams l6, 17 are suspended by means of arm members 25, 25a and 26, 26a from the drive control mechanisms located in gear boxes 1 l and 14, respectively. Thus, the drive control mechanism for the conveying system in cludes a main gear box 1 l and an auxiliary gear box 14 which are interconnected by a drive shaft 15. A motor and brake device I2 and a worm gear transmission 13 are provided in the main gear box 11. The conveying beams 16, 17 are suspended between and below the two gear boxes ll, 14.

Positioned within the main gear box 11 are two detent gearing mechanisms designated X and Y which control the movement of the conveying beams l6, 17 in a predetermined path to effect the movement of the workpieces to and from the forging dies. The mechanism of the detent gears moves in separate planes which are generally perpendicular to each other. These gears, thus, permit the energy from the motortransmission apparatus l2, 13 to be translated into respective three-dimensional movement necessary for the conveying beams 16, 17 to function.

The detent gearing X consists of crank 18, link 19 and two rocker arms 20 and 21. The crank 18 is driven by the shaft 22. A bell crank lever 23 connects the detent gearing mechanism X with the conveying arms 25 by means of connecting rod 24. (FIG. 1.) The rod 24 includes a resilient means such as a spring to snub and cushion the movements of the conveying arm 25. The conveying arms 25, 25a, 26, 26a are disposed at the sides of the gear boxes 1 l and 14, respectively, and are suspended for pivotal movement from cross beams 32, 32'. The lower ends of the conveying arms 25, 25a, 26, 26a are connected by means of swivel joints to respective ends of the conveying beams 16, 17. The transverse stroke of the conveying arm 25 is controlled by two draw cables 27, 28. These cables prevent the over stroke of the conveying beams l6, l7 and prevent possible damage to the control drive mechanisms. v

The conveying arms 25, 25a, 26, 26a include a piston-cylinder arrangement wherein each conveyingarm includes a piston rod 29, spring 30 and a piston 31. (FIGS. 1 and 3.) The cross beams 32, 32'to which the conveying arms are pivotally attached are mounted for pivotal movement about shafts 33, 33' in the gear boxes 11 and 14, respectively. Disposed within the cross beams 32, 32' are gear racks 34, 34'. One end of each rack 34, 34' is attached to an air cylinder device 35, 35; while the opposite end of each rack 34, 34 is connected by a rotatable joint to the link 36, 36 and the lever 37, 37. The levers 37, 37' are located in gear boxes 11 and 14, respectively. The lever 37 is driven by the power drive shaft 46 through the detent gear Y (see FIGS. 2 and 6). v

The detent gear Y consists of power crank 38, link 39, two rocker arms 40, 41 and lever 42 pivotally mounted on the shaft 43. The crank 38 is driven by shaft 46 from the motor transmission assembly 12, 13 as shown in FIG. 6. Bevel gears 44, 45 drive shaft 22 from the power drive shaft 46. Crank 18 of detent gear X is drivingly connected to the shaft 22. As can be seen in FIG. 6, the detent gear power cranks 18, 38 move in planes which are perpendicular to each other.

The gear racks 34, 34' which are positioned within the cross beams 32, 32', respectively, mesh with pinions 47, 47 and crank arms 48, 48'. The cranks 48, 48 are connected by means of toggle mechanisms to the conveying arms 25, 25a and 26, 26a. The toggle mechanisms are composed of the pivotally connected links 49, 49, 50, 50' and 51, 51' (see FIG. 3). The links 49, 49' are guided in vertical slots to provide vertical reference axes between the paired conveying arms 25, 25a or 26, 260.

If desired, additional conveying arms 52, 52a as shown in FIG. 5 can be included to provide parallelguiding of the conveying beams 16, 17. The pair of conveying arms 25, 25a and the auxiliary guiding arms 52, 52a may be adjusted in their position relative to each other by means of the adjusting screws 54, 54a. By these adjusting means the conveying beams 16, 17 can be maintained in parallel relationship even after considerable use.

In this conveying system, the ,detent gears X and Y are interconnected by the drive shafts 46 and 22 in such a wayv that the Y gear provides for opening and closing and the lifting functions of the conveying beams; while the X gear provides the longitudinal movement function. Through the various linkage arrangements, one detent gear is blocked while the other is in motion. Thus, movement of the conveying beams 16, 1 7 is performed in sequential predetermined movements in one plane at a time.

As shown in FIG. 7, if the lifting or conveying beams 16, 17 commence a work cycle at position 0, i.e., the conveying beams are spread and are in the lower position or receiving position, detent gear Y becomes operative. The lever 42 is pivoted due to the crank 38, link 39. and rocker arms 40, 41 being displaced out of the extended position. The pivoting movement of lever 42 is transmitted through the shafts 43, 43 to the levers 37, 37 The two shafts 43, 43 in the respective gear boxes are connected together by the shaft and the links 53, 53'. As the levers 37, 37' are pivoted the racks 34, 34' are moved by the links 36, 36. Thus, the racks are displaced in the longitudinal direction until the levers 37, 37' and the links 36, 36' are extended in an aligned position (see FIG. 2).

As the racks 34, 34'- move longitudinally the pinion gears 47, 47' rotate the crank 48, 48'. Thus, the conveying beams 16, 17 are retracted toward each other in a gripping movement by the raising of the links 49, 49 and links 50, 50, 51, 51-.

As the levers 37, 37' move beyond the aligned position with links 36, 36', the racks 34, 34 and cross beams 32, 32' are raised by the links 36, 36'. As shown in FIG. 1, the cross beams 32, 32' are pivotally mounted around shafts 33, 33 so that as the cross beams 32, 32' are rotatably lifted the conveying beams 16, 17 are lifted. By this means the workpiece which is gripped by the lifting or conveying beams 16, 17 is raised to an elevation above the bottom forging die. Air cylinders 35, 35' are included at one end of the racks 34, 34' and are actuated during the lifting process to cause the conveying beams 16, 17 to more securely grip the workpiece. When the upwardmost movement of the conveying beams 16, 17 has been concluded, locking of detent gear Y takes place and motion of the detent gear X commences The power crank 18, as shown in FIG. 1, retracts the link 19 which pulls the rocker arms 20, 21 out of extended, aligned position and rotates the bell crank lever 23 and shaft 234. The lower end of the bell crank lever 23 is connected to the conveying arm 25a by the resilient connecting rod 24. The conveying arm 25 is connected by a second resilient connecting rod 24 through a lever 23a rotated in unison with the bell crank 23 by the shaft 23a. The conveying beams l6, 17 are thus moved longitudinally to the depositing position. As mentioned previously, the conveying stroke is limited by the draw cables 27, 28. The cables are provided to limit the conveying stroke since it has been found that the use of a stop plate does not provide the necessary wear resistance. The cables are dimensioned so as not to interfere with the movement of the conveying beams and workpieces. Any over stroke of the bell crank lever 23 is absorbed by the resilient means in the connecting rods 24.

At the end of the conveying stroke, the gear X is locked and the gear Y commences motion for the termination of the conveying process by lowering and spreading the conveying beams in a reverse sequence. The detent gear X then provides for the return travel of the conveying beams, after termination of the clam ping condition. The forging press ram stroke is then triggered by any known manner upon the return travel movement of the conveying beams.

Each of the conveying arms 25, 25a and 26, 26a are composed of a piston-cylinder device which includes connecting rod 29, piston 31v and piston biasing spring 30. The explanation hereafter given will be made with reference to one conveying am, but it is understood that all the conveying arms are similar. During normal operation, a constant air pressure is applied to the upper portion of the piston-cylinder device. The working pressure and dimension of the piston is designed so that a force is generated which is greater than the biasing force of the spring 30. Thus, the constant application of pressure to the cylinder unit during normal operation will maintain the piston rod in an extended position. If the lower forging die is to be removed, the

conveying beams 16 and 17 are raised to provide the necessary clearance by cutting off the fluid pressure from the piston 31. The biasing force of the spring 30 will automatically raise the piston rod 29 to lift the conveying beams 16 and 17 out of the way. Thus, the lower die can be extracted as desired. The subsequent pressuring of the piston-cylinder unit will again return the conveying beams to their normal position.

The biasing spring 30 also serves to allow for deflection of the lifting or conveying beams l6, 17 if an unintentional forging press stroke should occur out of sequence. This stroke would destroy or damage the conveying beams and possibly the drive control mechanism if the beams happen to be in the retracted position at the time.

A releaseable connection is provided between the piston 31 and the piston rod 29 so that if excessive force is applied to the conveying beams this force will release the piston rods 29 from the drive control mechanism. Any type of a releaseable connection such as a frangible joint, force-fit joint or other non-separating but releaseable connection can be utilized. The drive for the automatic conveying system is immediately shut off when the emergency occurs.

In another embodiment of this invention, as shown in FIGS. 9 and 10, a hydraulic drive arrangement is provided for the movement of the conveying beams 16 and 17. Identical units are provided on each side of the forging press frame and are identical in structure. For the purpose of this disclosure, the following description although referring to one unit is intended to describe both units.

The conveying arms 25, 25a are pivotally mounted at 56 and 57 on the slide plate 55. The slide plate 55 is displaceable along the transverse guide rod 58, allowing the conveying beams 16 and 17 to move in the longitudinal direction. The guide rods 58 are guided at their ends on the vertical columns or rods 59. The vertical adjustment of the slide plate 55 is effected by means of a fluid motor or piston-cylinder unit 60 mounted for pivotal attachment at 61. The displacement of the slide plate 55 in the transverse direction along the guide rod 58 is performed by means of the fluid motor or pistoncylinder unit 62 pivotally attached at 63 to the frame. A third fluid motor 64 is pivotally attached to the slide plate 55 at the pivotal connection 65. The piston rod of the motor 64 acts on a pin 66 which moves in the slot 67. The links 68 and 69 are articulatively attached to the pin 66 and connected respectively to the conveying arms 25, 25a. By extending the piston rod of the fluid motor unit 64, a spreading movement of the conveying beams 16, 17 is effected to either clamp or release the workpiece as desired.

it is understood that a motor pump assembly can be provided to obtain the necessary fluid pressure for actuating the fluid motor assemblies. An automatic arrangement controls operation of the fluid motor units by means of hydraulic valves which are operated by the linkage arrangements described herein. As another embodiment, a simple cam mechanism can be utilized to provide the desired sequential step operation of the hydraulic valves While the conveying device has been shown and described in detail, it is obvious that this invention is not 6 claimed, without departing from the spirit of this invention.

Having thus set forth and discussed the nature of this invention, what is claimed is:

l. A workpiece transferring apparatus for a drop forging press which includes a frame structure, a power driven ram and top and bottom forging dies which are moved in reciprocating motion with respect to each other by the power driven rarn to shape a workpiece placed therebetween, said transferring apparatus comprising:

a. conveying means adapted to straddle the forging dies for moving workpieces,

b. said conveying means including a pair of conveying beams having a gripping means near their central portion for cooperatively gripping opposite sides of a workpiece,

c. drive control means, and

d. suspension means arranged to support and suspend said conveying means from the drive control means,

e. said suspension means including a plurality of support members which are pivotally attached to the ends of said conveying beams,

f. each said support member comprising a pistoncylinder means adapted for positioning said conveying beams in an extended and a retracted position with respect to said forging dies,

g. each said piston cylinder means including a biasing means to bias the piston cylinder means towards the retracted position,

h. said control means being adapted to move said suspension means and conveying means in unisonous, predetermined movement whereby the workpiece is moved to and from the forging dies.

2. A transferring apparatus as defined in claim 1 wherein said piston-cylinder means is normally held in the extended position against said biasing means by the continuous application of fluid pressure thereto.

3. A transferring apparatus as defined in claim 1 wherein each of said piston-cylinder means includes a piston and piston rod which are interconnected by a releasable means so that said piston and piston rod will separate if an excessive force is applied to said conveying means.

4. A workpiece transferring apparatus for a hot forging drop press which includes a frame structure, a main drive for a power driven ram and top and bottom forging dies which are moved in reciprocating motion with respect to each other by the power driven ram to shape a workpiece placed threrbetwee, said transferring apparatus comprising:

a. conveying means adapted to straddle the forging dies for moving workpieces,

b. a separate drive control means independent from the main drive of the hot forging press,

c. said independent drive control means being located above the bottom forging die,

d. said conveying means including a pair of transfer beams for receiving the workpiece between them, and

e. suspension means including support members each pivotally attached at one end thereof to an end of a transfer beam and attached at the other end thereof in a Cardan like manner to cross beams 9 10 that are pivotally mounted around shafts located predetermined cyclic path. on each side ofthe press, 10. A transferring apparatus as defined in claim 4 f. said drive control means includes gear means for wherein effecting longitudinal and transverse movement of aid ear means includes a pair of detent gear means the transfer beams via the suspension means in uni- 5 hi h i arranged to v s id transfer beams in sonous, predetermined movement whereby the m ll perpendicular l workPlece to and from the forging dles- 11. A transferring apparatus as defined in claim 5 5. A transferring apparatus as defined in claim 4 wherein Whefem i said gear means includes at least two detent gear 831d Support members l f p'ston'cylmder means which coact with each other to impart a premeans adapted for positioning said transfer beams determined cyclic movement to said transfer In an a :rctmcted Posmon beams in order to grip and convey the workpiece. spect to orgmg 12. A transferring apparatus as defined in claim 11 6. A transferring apparatus as defined in claim 5 wherein wherem 15 one of said detent gear means controls the longitudisaid piston-cylinder means, includes a biasing means to bias a piston member toward the retracted position while the free side of the piston member is under a constant pneumatic pressure whereby the piston force is dimensioned to be superior to the '20 spring force. 7. A device as defined in claim 4 wherein the swing movements of the transfer beams are limited by draw nal movement of said transfer beams and the other of said detent gear means controls the lifting and gripping movements of said transfer beams.

13. A transferring apparatus as defined in claim 11 wherein each said detent gear means includes a crank means, rocker arm means and link means arranged in a workable mechanism. to impart a predetermined cables.

8. A transferring apparatus as defined in claim 4 mechamca] mPvemem to transfer 'f wherein 14. A transferring apparatus as defined in claim 8 said gear means includes a main gear means located whefem on one side of the press frame and an auxiliary gear sald mam g means l detent p means located on'a side of the press frame opposite for p g closing, Mung and lowermg trans said main gear means, fer beams. said main gear means and said auxiliary gear means A tl'ansfefl'lng apparatus as efined n Claim 4 being interconnected by a drive shaft means. Where"! 9. A transferring apparatus as defined in claim 8 said gear means includes a detent gear having a link wherein means and a toggle-lever system mounted on a said main gear means includes at least one deten cross beam.

gear means for moving said conveying means in a 

1. A workpiece transferring apparatus for a drop forging press which includes a frame structure, a power driven ram and top and bottom forging dies which are moved in reciprocating motion with respect to each other by the power driven ram to shape a workpiece placed therebetween, said transferring apparatus comprising: a. conveying means adapted to straddle the forging dies for moving workpieces, b. said conveying means including a pair of conveying beams having a gripping means near their central portion for cooperatively gripping opposite sides of a workpiece, c. drive control means, and d. suspension means arranged to support and suspend said conveying means from the drive control means, e. said suspension means including a plurality of support members which are pivotally attached to the ends of said conveying beams, f. each said support member comprising a piston-cylinder means adapted for positioning said conveying beams in an extended and a retracted position with respect to said forging dies, g. each said piston cylinder means including a biasing means to bias the piston cylinder means towards the retracted position, h. said control means being adapted to move said suspension means and conveying means in unisonous, predetermined movement whereby the workpiece is moved to and from the forging dies.
 2. A transferring apparatus as defined in claim 1 wherein said piston-cylinder means is normally held in the extended position against said biasing meanS by the continuous application of fluid pressure thereto.
 3. A transferring apparatus as defined in claim 1 wherein each of said piston-cylinder means includes a piston and piston rod which are interconnected by a releasable means so that said piston and piston rod will separate if an excessive force is applied to said conveying means.
 4. A workpiece transferring apparatus for a hot forging drop press which includes a frame structure, a main drive for a power driven ram and top and bottom forging dies which are moved in reciprocating motion with respect to each other by the power driven ram to shape a workpiece placed threrbetwee, said transferring apparatus comprising: a. conveying means adapted to straddle the forging dies for moving workpieces, b. a separate drive control means independent from the main drive of the hot forging press, c. said independent drive control means being located above the bottom forging die, d. said conveying means including a pair of transfer beams for receiving the workpiece between them, and e. suspension means including support members each pivotally attached at one end thereof to an end of a transfer beam and attached at the other end thereof in a Cardan like manner to cross beams that are pivotally mounted around shafts located on each side of the press, f. said drive control means includes gear means for effecting longitudinal and transverse movement of the transfer beams via the suspension means in unisonous, predetermined movement whereby the workpiece is moved to and from the forging dies.
 5. A transferring apparatus as defined in claim 4 wherein said support members comprise a piston-cylinder means adapted for positioning said transfer beams in an extended and a retracted position with respect to said forging dies.
 6. A transferring apparatus as defined in claim 5 wherein said piston-cylinder means includes a biasing means to bias a piston member toward the retracted position while the free side of the piston member is under a constant pneumatic pressure whereby the piston force is dimensioned to be superior to the spring force.
 7. A device as defined in claim 4 wherein the swing movements of the transfer beams are limited by draw cables.
 8. A transferring apparatus as defined in claim 4 wherein said gear means includes a main gear means located on one side of the press frame and an auxiliary gear means located on a side of the press frame opposite said main gear means, said main gear means and said auxiliary gear means being interconnected by a drive shaft means.
 9. A transferring apparatus as defined in claim 8 wherein said main gear means includes at least one detent gear means for moving said conveying means in a predetermined cyclic path.
 10. A transferring apparatus as defined in claim 4 wherein said gear means includes a pair of detent gear means which is arranged to move said transfer beams in three mutually perpendicular planes.
 11. A transferring apparatus as defined in claim 5 wherein said gear means includes at least two detent gear means which coact with each other to impart a predetermined cyclic movement to said transfer beams in order to grip and convey the workpiece.
 12. A transferring apparatus as defined in claim 11 wherein one of said detent gear means controls the longitudinal movement of said transfer beams and the other of said detent gear means controls the lifting and gripping movements of said transfer beams.
 13. A transferring apparatus as defined in claim 11 wherein each said detent gear means includes a crank means, rocker arm means and link means arranged in a workable mechanism to impart a predetermined mechanical movement to said transfer beams.
 14. A transferring apparatus as defined in claim 8 wherein said main gear means includes detent gears adapted for opening, closing, lifting and lowering the transfer beams.
 15. A transferring appAratus as defined in claim 4 wherein said gear means includes a detent gear having a link means and a toggle-lever system mounted on a cross beam. 